THE AMERICAN BOTANIST 15 



performed in spring when the sap is beginning to rise. It is 

 advisable to put back the cork thus stripped, fastening it around 

 the trunk by means of wire and leaving it there for a time; 

 otherwise the trees are very liable to injury from dry, hot 

 winds. Wrapping the trees in this way also prevents a second 

 development of the worthless outer cork. The new cork is of 

 great value. It is deposited at the rate of .04 to .12 inch 

 annually. The first harvest is taken when the layer of cork has 

 reached the thickness of an inch. 



